Jakarta flooding: ”A depressing, but not impossible picture”

Jakarta’s ground water extraction, population growth and waste management problems are intrinsically linked to the city’s propensity to flood during the rainy season, say two World Bank experts.

Jakarta-based expert Fook Chuan Eng says while the these issues may paint a depressing picture, “it is not an impossible picture.”

The Bank is attempting to get government and other institutions together to address planning (rather than just engineering) issues related to flood management.

About 40 percent of downtown Jakarta lies below sea level. Authorities attempt to manage floods by diverting peak flows from upstream areas in the mountains around the city, directing water to the east and west of Jakarta via two major flood canals emptying out into Jakarta Bay. There are also 13 rivers and a large number of drainage channels within the city.

However the originally-planned drainage system is incomplete. The east flood canal was completed in 2011 but is not yet fully functional. And jurisdiction issues and conflicts are exacerbating the problem.

Indonesia is urbanising faster than any other Asian nation, including China. The population of Jakarta DKI is 9.6 million (2010 census) but most of the growth is in places such as Bogor and Depok. The population is 28 million in the greater Jakarta area.

Inadequate urban planning in the face of this population growth has created all sorts of other problems. The World Bank says increased generation and inadequate management of solid waste has contributed to waste-choked canals and floodways. 52.97% of Jakarta’s rubbish comes from households and much of it is organic waste (therefore compostable). Between 4500-5500 tonnes of rubbish is generated each day in Jakarta

The city is also sinking. Land subsistence continues at increasingly alarming rates, principally caused by intensive deep groundwater abstraction. Recent studies have found typical subsidence rates of 7.5-10cm a year.

Fook Chuan Eng says if groundwater abstraction continues at the current rate, Jakarta will sink by 5-6 metres by 2100.

The Bank says there are opportunities for the government of Indonesia’s development partners to support and assist with improving the operations and management of Jakarta’s flood management system.

For Senior urban economist Peter Ellis, s the seventh largest city in the world, Jakarta is not living up to its potential. He says while it may seem counter-intuitive, the population density of Jakarta should be higher.

Ellis says authorities need to attract more people to the city centre, rather than building toll roads and spreading the population. This would enable more efficient delivery of water, mass transport and other services.

“The challenge facing Indonesia is how to build vibrant cities, because they are necessary for growth,” says Ellis.